Mobile devices are widely used because they can be easily carried and provide a variety of functions such as a voice call function. Mobile devices serve as multimedia communication devices because they can transmit data and also provide various additional services.
Mobile device users can transmit data, such as messages, contents files, and such, to called parties via their mobile devices by selecting data to be transmitted and entering called parties' phone numbers or ID's to their mobile devices. These processes must be performed although the called parties are near the calling users. When the calling users do not know the called parties' phone numbers, they must first ask the called parties for their phone numbers. The calling users may then enter the called parties' phone numbers into their mobile devices and transmit messages to the called parties' mobile devices. This inconveniences the mobile device users.
In particular, when a mobile device user wants to send his/her electronic business card (e-business card) to multiple people, conventional data transmission system requires for the user to first input all of the called parties' phone numbers to his/her mobile device.
New systems are required to allow users to easily transmit data, such as messages, contents files, and such, from their mobile devices to external mobile devices.